Water Ingestion Into I/o Merc Engine

Whether fresh-water (closed loop) cooled or not, the raw water is still injected in to exhaust flow at exactly the same place and manner on the vast majority of such engines; via an inductor ring in the manifold riser or exit elbow.

 

yep and on millions of engines it causes no issues whatsoever
if you can make that higher than the engine then it works even better

 

I think perhaps Boatwiser could find the information he wants better by browsing Google images of boat exhaust systems for a suitable solution to what he wants that would suit his boat.Opinions deliberately misinterpreted just to try and put down differing ideas does not help any one.
I have spent many thousand of hours operating multi million dollars of equipment that use
the same principles as in boat exhaust systems and being able to actually see through transparent areas to see what is happening to water and air flows hot and cold.
I have spent a lot of time using the same principles to see how boat induction and exhaust systems behave in my own boat so I think I have valid but perhaps different opinions.

 

Mercruiser wet exhausts don't cause engines to die on 99% of sterndrive boats. Since yours had problems I'd get to the bottom of what happened as much as you can and see what can be changed. Is there room to add a riser spacer which is fairly cheap. Could even modify hatch if you have to. Had the flaps in the y pipe failed or does it have thru hull exhaust? If thru hull, what kind of external flaps - change them to a different brand. They're cheap. Could even move up exhaust tips if there's room for higher risers if they're getting slammed and you think that's how it failed.

 

My ideal for cooling a boat motor is to use a fresh water closed system with anti freeze and anti corrosive additives coupled with internal or external keel coolers or heat exchangers.
For the exhaust an all metal raw water cooled exhaust manifold, water jacketed exhaust pipes and mufflers with the cooling water exiting at the tail pipe to quieten sound.
Include emission control system in that plus exhaust oil and soot scrubbers.
And why not dry insulate the exhaust system so if water cooling fails you could still get home.
If you own a boat you are going to have a clean system some time soon and be chased up by regulatory bodies.

 

A few interesting wet exhaust comments.
www.fitzhughmedia.com/MBF/exhaust1.html

www.marinemechanic.com/site/page66.html